In a power plant, a generator is provided for generating electricity and is for example driven by a fluid energy machine. The fluid energy machine is a steam turbine or a gas turbine used in combination with a steam turbine. A power plant driven purely by a steam turbine (steam power plant, SPP) is conventionally used to provide base-load capacity, whereas a power plant driven by gas and steam (combined cycle power plant, CCPP) is started up and shut down as required for peak loads. In accordance with conventional power plant configurations, the steam turbine for a CCPP is characterized in that it is subjected to a high cyclic load, no takeoff being provided at the steam turbine. Contrary to this, in a conventional steam power plant, the cyclic load on the steam turbine is slight, a takeoff being provided at the steam turbine. The configuration of the CCPP steam turbine is therefore different to that of the SPP steam turbine.
Steam turbines conventionally have a low-pressure turbine whose inner housing is embodied as a welded construction. On account of the different strength requirements and design with respect to the takeoff to be provided in the case of the SPP steam turbine, the construction of the inner housing for the CCPP steam turbine is different to that of the inner housing for the SPP steam turbine. A stiffening cradle is conventionally provided at the takeoff point of the inner housing for the SPP steam turbine. Such a stiffening cradle need not be provided in the inner housing for a CCPP steam turbine as the CCPP steam turbine is not fitted with a takeoff. In addition, providing the stiffening cradle in the inner housing of the CCPP steam turbine would be disadvantageous as the stiffening cradle has, as a consequence of its construction, only a limited capacity for alternating loading, whereby the stiffening cradle, if provided in the inner housing of the CCPP steam turbine, would not be able to withstand the high cyclic loads. A different welded construction to that of the inner housing of the SPP steam turbine is therefore made available for the inner housing of the CCPP steam turbine. As a consequence, when producing steam turbines, the inner housing for the CCPP steam turbine and the inner housing for the SPP steam turbine are produced separately, wherein both inner housings are kept in corresponding storage. This, however, has the drawback that separate production with corresponding storage must be provided for both the SPP steam turbine and the CCPP steam turbine.